2021: Surveys for the state-threatened Eastern Hog-nosed Snake in south-central South Dakota
The Eastern Hog-nosed Snake (Heterodon platirhinos) is a medium-sized, state-threatened snake that is distributed across most of the eastern USA, throughout the Great Lakes region, and into the Great Plains. Within the Great Plains, Eastern Hog-nosed Snakes reach their northernmost extent in South Dakota. Previously, the Eastern Hog-nosed Snake was thought to be restricted to extreme southeastern South Dakota along the Missouri River in Clay and Union counties, until two additional records greatly expanded the putative distribution of this species in the state. The first was a specimen collected from Chamberlain, Brule County in 1943 (Biodiversity Collections, University of Texas at Austin [TNHC] 106094) that was part of a recently accessioned voucher specimen collection from South Dakota State University. The second was a photograph of an Eastern Hog-nosed Snake from Rosebud Reservation, Todd County taken in 2017 (HerpMapper [HM] 193175). These new records are ca. 221 and 324 km west of the nearest record of Eastern Hog-nosed Snake in Clay County (University of Nebraska State Museum [UNSM] ZM-16478), represent the only known records for this species in central and western South Dakota, and provide evidence that populations of Eastern Hog-nosed Snakes occur along the Missouri River and riparian corridors in south-central South Dakota. To better understand the distribution and occurrence of Eastern Hog-nosed Snakes, I will conduct a series of targeted surveys for this species in south-central South Dakota.
Adult (left) and juvenile (right) Eastern Hog-nosed Snake (Heterodon platirhinos).
2020: New resources and continued engagement to better inform the public on the amphibians and reptiles of South Dakota
This project addresses two important needs: 1) to educate the general public about amphibians and reptiles in South Dakota, and 2) to encourage and facilitate citizen science reporting of observations of amphibians and reptiles. Ballinger et al. (2000) estimated that 56% of the expected distributions of species at the county-level had corresponding specimen records. Ballinger et al. (2000) compared the expected county-level distributions of species with what was actually represented by specimen records and suggested that only 56% of the predicted distributions were verified by specimen records. Additionally, Ballinger et al. (2000) stated that an expected 223 county records remained to be documented at that time. Fieldwork conducted from 2012–2018 and a thorough examination of existing museum records resulted in 224 new county level records for amphibians and reptiles in South Dakota. Even though these new records have helped to increase our knowledge of species distributions within the state, it remains clear that additional gaps in our understanding remain. Given these remaining gaps, the involvement of citizen scientists in reporting observations provides an opportunity to increase our knowledge of species distributions, especially in areas dominated by private property. Citizen science has gained traction recently as a means to obtain important information on species in a region while simultaneously engaging community members in the natural world around them. Not only can citizen science observations help to fill in remaining gaps in species distributions, but contemporary records allow for a more current understanding of species distributions in South Dakota, which is especially important given that 68% of amphibian and reptile records in the state are more than 20 years old. Given the success of the website in generating new, contemporary records of amphibians and reptiles in the state, I wish to expand the website by developing additional features and continuing to encourage the public to submit their own records.
Davis DR. 2020. New resources and continued engagement to better inform the public on the amphibians and reptiles of South Dakota. Final report to South Dakota Game, Fish and Parks. 38 pp.
2018: Surveys for the state-endangered Lined Snake along the lower James River Valley
The Lined Snake (Tropidoclonion lineatum) is a small, state-endangered fossorial snake that is distributed across a large portion of the Great Plains. Populations of the Lined Snake span from southern Texas and reach their northern limit in southeastern South Dakota and southwestern Minnesota. Within South Dakota, the Lined Snake was thought to occur only in habitats along the Big Sioux River watershed, until a specimen was collected near the James River in Hutchinson County in October 2017. This recently collected snake represents the most northwestern occurrence for this species, provides evidence that populations of Lined Snakes may exist outside of the Big Sioux River watershed, and suggests that the distribution of Lined Snakes in South Dakota may be greater than expected. To better understand the distribution and occurrence of Lined Snakes in southeastern South Dakota, a series of targeted surveys will be conducted for Lined Snakes along the lower James River Valley.
Davis DR. 2018. Surveys for the state-endangered lined snake (Tropidoclonion lineatum) along the lower James River valley. Final report to South Dakota Game, Fish and Parks. 25 pp.
Adult Lined Snake (left) and diagnostic half-moon patterning on the underside of Lined Snakes (right).
2017: Status of the False Map Turtle in Lake Oahe, South Dakota
South Dakota Game, Fish and Parks has funded a two-year survey effort to examine whether the state-threatened False Map Turtle (Graptemys pseudogeographica) is still present in Lake Oahe, a large reservoir along the Missouri River, north of Pierre. Daming of the Missouri River and the formation of large reservoirs has resulted in habitat degradation and loss, and likely the extirpation of this species form a large part of their historic range. Initial results from 2017 suggest this species is extirpated from the main area of Lake Oahe; however, this species may still be present in the large river drainages on the western shore of Lake Oahe (Cheyenne River, Moreau River, Grand River). Despite its extirpation along most of Lake Oahe, False Map Turtles remain numerous from free-flowing, more natural segments of the Missouri River, such as the 59-mile Missouri National Recreational River from Yankton to Sioux City.
Kerby J, Davis D, Kase A. 2019. Surveys for false map turtle and identification of key nesting sites in the upper Missouri River of South Dakota. Final report to South Dakota Department of Game, Fish and Parks. Unpaginated [9 pp.].
Adult male (left) and female (right) False Map Turtles (Graptemys pseudogeographica).
2016: Creating online resources to engage South Dakota citizens in amphibian and reptile identification and conservation
Resources for the general public concerning South Dakota amphibian and reptile species identification, distribution, and natural history are limited. Although a field guide on South Dakota amphibians and reptiles exists, most individuals use the internet to search for answers regarding species identification, natural history, and state distribution. Currently, no such information is available online and therefore, it is critical that a resource is developed. To address the need of having a user-friendly website with information on amphibians and reptiles of South Dakota, we have recently launched the website: www.sdherps.org. This web platform contains species accounts, distribution maps (based on over 11,400 vouchered specimen records[as of February 2017]), and photographs of all 45 species of amphibians and reptiles in South Dakota. Additionally, we aim to promote the submission of citizen-generated observations of amphibians and reptiles through this website and its partner, HerpMapper. The combination of a website devoted to South Dakota amphibians and reptiles, and increasing public submissions of field observations, will allow for us to provide a resource to the general public and generate occurrence data that can be used by researchers and South Dakota Game, Fish and Parks.
Davis DR, Smith CE, Becker D. 2018. Creating online resources to engage South Dakota citizens in amphibian and reptile identification, distribution, and conservation. Final report to South Dakota Game, Fish and Parks. 49 pp.
User-submitted observations of amphibians and reptiles from across South Dakota during 2017. Species from L to R: Western Tiger Salamander, Plains Spadefoot, Prairie Skink, Ring-necked Snake, Western Foxsnake.
Please contact me with a short synopsis of research projects to be added to this page.